微机械可变电容制作工艺中的牺牲层释放和残余应力分析

Release Process of Sacrificial and Analysis of Residual Stress in the MEMS Variable Capacitor Manufacture

运用高选择比的特别配方来释放MEMS可变电容制作工艺中的牺牲层,以保护上级板金属铝层,同时很好地释放牺牲层磷硅玻璃。探讨了上级板的粘附问题,对工艺中影响成品率的关键因素残余应力进行了模拟,当温度T为350℃时,平面应力P为811.6 MPa;当温度T为500℃时,平面应力P为1 185.9 MPa。分析了残余应力对上级板的影响和对悬臂梁的等效弹性系数的影响。

The special high - selective directions is applied to release sacrificial layer of the MEMS variabte capacitor manufacture, so as to protect the top Aluminum and etch the sacrificial layer phosphorus Silicon glass. The stick problem of the top plate is also discussed. The residual stress which is the key factor affecting turn off rate is researched. When the temperature is 350 ℃ ,the plate stress is 811.6 MPa,when the temperature is 500℃ ,the plate stress is 1 185.9 MPa. Also its influence to warp of the top plate and equivalent elasticity coefficient of cantilever beam is discussed.